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Family ALEPOCEFHA.LIDAE 
Body elongated, compressed# Mouth moderate or large, upper edge com¬ 
posed of maxillaries and premaxillaries, latter placed along front and lower 
edge of former# Maxillary with posterior supplemental bone. Barbels none. 
Teeth feeble, on premaxillaries and mostly on palatines. Nostrils close to 
eye, Opercles complete, very thin# Gill opening very wide, partly covered 
by continuation of skin of head and by gill membranes, which free from 
isthmus and overlapping each other# Gill rakers long, numerous# Pseudo¬ 
branchiae present# Head mostly naked. Scales thin, cycloid, at least in 
lateral line# No adipose dorsal# Anal more or less below dorsal# Pectoral 
« 
rather high. Ventral nearly median, sometimes absent. Vent behind middle 
of body. 
Deep sea fishes of similiar fundamental structure to the Clupeidae 
and Salmonidae, but without the postclavicle or an adipose fin, and both 
dorsal and anal posterior or opposed. The skeleton is feebly ossified and 
the air bladder absent# 
There is less uncertainty regarding the habitat of this family than 
in respect to that of some of the others# Structure, blackness of integument, 
food, and the condition of the specimens on arrival at the surface all favor 
the conclusion that these fishes dwell close to the bottom, himdreds of 
fathoms below the surface# The large eye is a distinguishing feature of the 
Alepocephalidae and its possession must be regarded as proof of the presence 
of light either in the bodies of the other inhabitants of the sea bottom, 
fellows, enemies, prey, etc#, or in the medium in which the family lives, 
one or the other or both# In the absence of luminous organs, except, it may 
